1. Field of the Invention
This invention relates to the field of fog emitting practice war heads. More particularly, the invention pertains to the field of practice war heads utilizing fog producing substances based on mixtures of carbon halogen or halogen carbohydrate substances and reactive metal or metal oxide powders.
2. Description of the Prior Art
For producing substances based on hexachloroethane and metal powders are known and have been employed in fog devices for years in view of their good fog producing properties. Also known are fog producing substances based on hexachloroethane and metal powders, comprising also a metal oxide as an additional component, for example zinc oxide (Modern Pyrotechnics by Dr. H. Ellern, 1961, page 277). Suitable smoke and fog producing substances are described in British Pat. No. 127 031, in which it is also disclosed that such substances can be ignited, amongst others, by so-called "alumino-thermal" mixtures, which are mixtures of metal powders and oxygen-liberating substances.
As a rule, fog producing substances based on hexachloroethane and metal powders are only shaken loosely into place, since they are sufficiently stable in storage only in loose form. There are however special receptacles available which may be highly compressed. All of these substances packings however require a relatively long time before the fog reaction proceeds at full rate. The time for reaction to commence can however be shortened by the addition of very specific chemicals, such as, aluminum pyorgenic powder instead of aluminum powder. At the same time however, operational safety is affected.
It is therefore not possible to ignite and distribute a conventional hexachloroethane fog packing with an explosive load without significantly influencing the fog producing capabilities. Firstly, the time of action of the ignition flame is too short, and secondly, the reaction components are distributed before they can react with one another. Additionally, the use of an explosive leads to difficulties with respect to the operational safety and storage.
Compression of conventional mixtures of hexachloroethane and metal powder leads to such an activation that the reaction partners react incompletely with one another. This procedure however leads to a deactivation during storage and is the reason for the non-compressibility of conventional hexachloroethane packings.
The abovementioned disadvantages render it difficult to employ hexachloroethane fog producing packings in devices in which the sudden formation of a fog marking is important, such as is the case with a practice war head.